As the cost of energy has continued to rise steadily in significant proportions in recent years, the need for economic and efficient heating means has become great. This need has become particularly acute in commercial and industrial settings because of the specific problems encountered in those areas. In the commercial setting because of the frequent presence of computer related business equipment, it is often desirable to maintain the entire business or office environment at a cooler temperature than may be comfortable for most personnal. It is also desirable to avoid heating the entire environment in order to minimize energy comsumption and expense. However, in office settings such efforst at energy savings have typically been counter-productive when sedentary personnel have required electrical space heaters for personal comfort. Such heaters while serving to supply heat to specific areas, consume substantial quantities of energy and present such hazards as overheating, fire and electrical shock.
Further problems are presented in industrial environments such as factories, mills and shops wherein the entire area of a facility to be heated may be so huge that maintaining the entire area at a temperature comfortable to personnel is virtually impossible and, in any event, economically unfeasible. Supplemental heat sources of various types have been used in industrial settings, such as electrical space and overhead radiation heaters, catalytic space heaters, forced air space heaters, and even open flame heaters. In the main, such heaters have proven to be unduly expensive to operate and maintain, inadequate at maintaining a comfortable temperature, and extremely hazardous in certain types of industrial workplace settings.
Another means of heating localized areas which has been proposed has been the use of floor mats or pads containing an electrical heat source to provide an indirect type of heat emanating from floor level for a particular area. Such pads have not been fully satisfactory either, however. Firstly, these pads have typically utilized a heating circuit including a length of resistance wire which, when energized with electrical current, generates heat. While this is a relatively simple type of heat source, it is one subject to being unreliable and unsafe. Fracture of the resistance wire can occur anywhere in the pad as a result of simple wear, or as the result of any number of causes such as from the spiked heel of a lady's shoe or from a falling tool. Such a fracture can serve to render the entire heating capability of the pad inoperative, and such a fracture can also result in deadly electrical shock or a short which can cause a fire or explosion. For these reasons, these pads have so far not been popular in commercial or industrial surroundings where they would likely be subjected to substantial foot traffic or where moisture or hostile chemicals could be expected to be encountered.
Although improvements have been made in heating pads such as by making the heat source less vulnerable to rupture and less a shock hazard, so far as applicant is aware prior to this invention, there still has been no electrical floor heating pad available for commercial or industrial uses that could satisfy Underwriters' Laboratories safety standards. Also, so far as applicant is aware prior to this invention, there has been no electrical heating pad available which eliminates static electricity build-up on the surface of same. In most offices and plants, the presence of static electricity can present substantial problems to personnel and equipment.